There's a reason you've never heard of the Portuguese soccer club Uniao de Leiria.

After climbing to the upper rankings of the national first division a decade ago, the team spiraled downward, dropping to the second division and struggling to pay its bills and players' wages. In one match, it managed to field only eight of 11 players. Two years ago, it slipped into bankruptcy.

In July, the club, located in the western city of Leiria about midway between Lisbon and Porto, appeared to have found a savior: a Russian businessman who ran a Moscow agency that represented aspiring Russian players. With an influx of fresh-faced Russian recruits and new investments, the club rose this week to the top of its sub-group in the third division and was on its way up to the second.

That outcome got a lot more complicated on May 4 when Portuguese police arrested the businessman, Aleksandr Tolstikov, and two other colleagues, accusing them of being part of a conspiracy to use the club to launder money from Russian organized-crime groups.

The arrests have opened another tiny window into the vast flows of money sloshing through world soccer, and European leagues in particular.

"Am I surprised? No," said Declan Hill, a Canadian researcher and author of the 2008 book The Fix: Soccer And Organized Crime. "What I am surprised about is that Portuguese police moved to do something and arrest these individuals."

As part of the raids, known as Operation Matrioshka -- a reference to traditional Russian nesting dolls -- financial police also raided the Uniao de Leiria offices, north of Lisbon, along with those of three better-known soccer clubs: Sporting Lisbon, Benfica, and Sporting Braga.

The website of Portuguese soccer club Uniao de Leiria

The European Union's law-enforcement agency, Europol, said that under an arrangement that began in 2008 the Russian gang searched for European soccer clubs that were having financial problems. They then took financial control of the clubs and used them as a front for a network of holding companies, through which money was then laundered.

The yearlong investigation was prompted by the "high standards of living" of the suspects, who imported "large amounts of cash from Russia to Portugal," Europol said.

Little is known of Tolstikov's history. Russia media said he was a native of Moldova and an aspiring soccer player who later worked as an agent representing young Russian athletes. A Moscow-based agency, D-Sports, lists him as the principal owner.

A Russian man who answered the phone number listed on the D-Sports website for Tolstikov said he knew nothing of him or the agency.

One of the other arrested men was Sergei Runitsa, who is listed as D-Sports' representative in Portugal. Calls and text messages sent to the number listed on the website also went unanswered. The third arrested man was identified as a Portuguese bookkeeper for the Leiria club.

In an interview he gave to the St. Petersburg news portal Fontanka.ru not long after the purchase of the Leiria club was announced, Tolstikov said that he held 60 percent of the club's shares. He also said he intended to use the club as a training ground for aspiring Russian soccer players, particularly those connected to the St. Petersburg powerhouse Zenit.

Last year, the club listed seven Russians on its roster.

Return On Investment

Hill, the Canadian researcher, said the Leiria case by far isn't the first case of organized crime groups allegedly using European soccer clubs to launder money. He said similar situations have occurred in lower-tier leagues in Belgium, Finland, and Italy in past years, though not necessarily involving Russians.

Europe is seen as at particular risk, given that many of its leagues are known as attractive investments. That's particularly true of top-flight teams -- Manchester United and Barcelona are among the best examples -- who have drawn in billionaires from Qatar, Russia, China, the United States, Thailand, and elsewhere.

In a 2009 report, the Financial Action Task Force, an intergovernmental agency focused on money laundering, warned specifically about the danger of criminal gangs using soccer clubs to launder illicit funds, and cited nearly two dozen examples.

Where Russian investment in European teams is concerned, the best-known case is in the English Premier League, where the club Chelsea was bought in 2003 by Roman Abramovich. It's now ranked among the world's most valuable sport franchises.

An ally of President Vladimir Putin, Abramovich made his fortune in Russia's aluminum industry and is now one of the country's wealthiest men.

One of Abramovich's first hires upon buying Chelsea was Jose Mourinho, a Portuguese coach who had orchestrated eye-catching victories for powerhouse club Porto.

Before Porto, Mourinho managed a similarly fast string of victories at Uniao de Leiria, where he worked in 2001-02. After his departure, the club slipped in its ranking, dropped into lower divisions, and entered bankruptcy sometime after 2012.

Tolstikov bought the club three years later, according to Europol.

Eugenio Querios, a reporter for the Portuguese sports newspaper Record, told RFE/RL that many soccer circles were surprised last year when the Russian investors bought into Leiria, given how small and low in the rankings the team was at the time.

He said that until this week's arrests, there was no indication of any illegal activity at Leiria.

Mourinho, who left Chelsea in December, has said nothing publicly since the news broke and, to date, there is no public indication of a connection between him and Uniao de Leiria's Russian owners.

For its part, Gestifute is run by Jorge Mendes, a Portuguese citizen who is renowned in the soccer world for representing not only Mourinho but international stars like Real Madrid's Cristiano Ronaldo. He brokered Mourinho's 2003 hiring by Chelsea, and two years ago helped broker the sale of top Spanish league team Valencia to a Singaporean businessman.

As with Mourinho, there is no indication to date of a connection between Uniao de Leiria's alleged role in criminal activity and Mendes.